Bicycles are a popular and efficient form of transportation which allows riders to travel over long distances with relative ease. Bicycles are also environmentally friendly and allow riders to exercise while they travel. As bicycle designs have progressed, numerous improvements have been implemented to enhance various aspects of bicycle performance.
Some modifications, like multi-gear drive systems, make bicycles easier to operate over hills and during periods of heavy wind. Additionally, new seat designs have made bicycles more comfortable, increasing the distance they may be ridden. Some bicycles, like recumbants, even allow riders to assume a reclined orientation during travel. Other bicycles include provisions to accommodate more than one rider simultaneously. Still other bicycles, like those of U.S. Pat. Nos. 4,400,003 and 5,052,706 have components that are selectively collapsible to promote easy storage and safe shipping.
In addition to providing a practical means of transportation and a convenient source of exercise, bicycles are often used as a source of entertainment. For example, many riders explore rocky terrain on so-called “mountain bikes.” This type of bicycle typically includes a shock absorbing suspension system that improves control over uneven surfaces. Suspension systems reduce rider fatigue by absorbing impacts that would otherwise be transmitted directly to the rider. An example of a suspension-including bicycle is disclosed in U.S. Pat. No. 5,658,001.
Mountainous terrain is not the only location traversed by thrill-seeking bicycle riders, however. Many riders choose the bicycle as a means of simulating temporary flight. Typically, this flight experience involves riding a bicycle at a high speed up, onto, and over an inclined ramp. With a ramp jump, the bicycle's momentum carries the bicycle and rider through the air. Other riders, such as those riding on mountainous terrain, will ride down large hills and jump off ledges as they go. Some city riders will ride around city streets jumping off of, and over, any obstacles they encounter as they ride.
But not all riders have access to ramps or mountains to ride on, but still want the thrill of jumping their bicycles as they ride. While city funded, or private, ramp parks are developing in certain areas, there are heavy constraints on access for riders. Alternatively, if a rider wanted to build their own ramp park they would not only need the space to build it, but also have the money to buy or build the ramps, which can be a prohibitively expensive cost. Using a mountain trail or a city street for recreational jumping is more cost effective, but comes with other restraints. Not all areas have easy access to mountain trails, or even any access. Even when accessible, mountain trails require maintenance or use and weather can lead to their eventual destruction. City streets are often convenient for riders, but the added risks of cars that might hit the rider, or pedestrians that the rider might hit make the liability of trick riding and jumping in these areas prohibitive. These constraints are limiting, and prevent a rider from the thrill and enjoyment of jumping their bike at any and all times, even as they commute from one place to another.
U.S. Pat. No. 5,301,969 is one known disclosure that provides a dual frame bicycle for purposed of jump simulation. The bicycle converts rotational energy from the bicycle wheel into translational energy used to make the bicycle leap. The '969 device is formed from two frames and employs a hooked pole that selectively engages a pin affixed to the bicycle rear wheel. The two bicycle frames are spaced apart by elastic members, and using the hooked pole to engage the rear wheel pin draws the two frames together, storing potential energy in the elastic members. The pole remains hooked to the wheel pin until the wheel has rotated a predetermined distance, at which point the hook is released. When the hook is released, the energy stored in the elastic members is released, forcing the bicycle frames apart and causing the bicycle to jump. The '969 patent requires a two frame and complex construction that is cost prohibitive and, once the bicycle begins to store energy, a jump is unavoidable. Even if it were possible to wrench the hook free from the wheel pin before the wheel had rotated through the hook-releasing distance, the already-stored energy would still be released. As a result, a rider attempting to abort a jump will still be lifted before coming to rest. This design also makes it difficult for a rider to increase or decrease the amount of lift, as needed. The '969 device also produces consistent amounts of lift which may not be appropriate for all situations during a given bicycle ride.
U.S. Pat. No. 6,558,297 discloses a locomotive device, such as a pogo stick, using a bow spring as the energy storage device. The bow spring in the form of a high-performance composite spring material such as fiberglass/epoxy or graphite/epoxy capable of storing at least two times more energy than a conventional steel coil spring having the same weight. The device uses a roller to guide a plunger to further improve the overall efficiency and performance of the device.
Applicant's U.S. Pat. Nos. 6,209,899 and 6,220,614 disclose bicycles having energy conversion construction that permits a rider to selectively elevate a bicycle frame during operation. A positioning systems convert's rotational energy from one of the wheels into translational energy causing the frame to elevate.
Accordingly, a need exists to provide a system that allows a user to jump their bicycle at any and all times that a rider chooses. A system which allows a bicycle rider to enjoy the thrilling stunt activities of jumping a bike on any terrain, including flat ground, while still providing the energy efficient, environmentally friendly exercise and transportation features of a traditional bicycle.